Sony TRINITRON KV-27S42 Service Manual page 7

KV-27S42/27S46/27S66/29AL42/29AL42C/29AL66/
29AL66C/29SL42/29SL42C/29SL46/29XL42M
Self-diagnostic Circuit
Y/CHROMA JUNGLE
FROM
21
CRT
FROM
IC521 18
PIN 7
+B overcurrent (OCP)
Vertical deflection stopped
White balance failure
IC301 IC541
V. OUT
IK IN
REF
HP/PROTECT
35
SDA
Occurs when an overcurrent on the +B (115V) line is detected by pin 18 of IC301. If the voltage
of pin 18 of IC 301 is less than 1V when V.SYNC is more than seven verticals in a period, the
unit will automatically turn off.
Occurs when an absence of the vertical deflection pulse is detected by pin 17 of IC001. Power
supply will shut down when waveform interval exceeds 2 seconds.
If the RGB levels* do not balance within 2 seconds after the power is turned on, this error will
be detected by IC301. TV will stay on, but there will be no picture.
*(Refers to the RGB levels of the AKB detection Ref pulse that detects 1K.)
IC001
SYSTEM
IO-BDAT
3 17 I-PROT
O-LED
37
IO-SDAT
— 6 —
IC003
MEMORY
B-DAT
36 5
18
DISPLAY